Why have Hollywood writers called a strike?

TV and movie writers, represented by the Writers Guild of America, had been negotiating with studios and the entertainment industry off and on since the summer about compensation issues. Many issues were on the table, but the parties reached an impasse over the writers' demand for a larger share of profits from DVD sales and revenue from viewings of their work on the Internet. They also want a percentage of growing revenue in new distribution channels — mobile viewing, for instance, and other new ways of watching the shows they write.

Where do the studios stand?

The studios, represented by the Alliance of Motion Picture and Television Producers, say it's still unclear how much revenue those new-media distribution channels are going to produce — and where the money will be coming from. They proposed a study to look for answers, but the writers reject such studies as irrelevant. They say they're entitled to a share of the profit on any material generated through any new technology, even if that compensation is small.

What happens now that a walkout has been called?

The immediate effects will be apparent on TV, where viewers are likely to start seeing more reality shows, which don't fall under guild jurisdiction, in place of regular scripted programming. (Think singing, dancing and weight-loss contests.) Some networks will show reruns, while some are looking at programming that hasn't been on their air before. NBC, for example, has considered running the original British version of The Office.

But the networks can't immunize themselves entirely, or so the writers argue. They say that running heavy loads of reality TV on all the major networks will have broadcasters stepping on each others' toes, competitively speaking.

As for movies, the effects will be less obvious in the short run, since big-screen production takes longer. The strike probably won't affect what you see at the multiplex for more than a year.

When was the last time this happened?

The last time writers went on strike was in 1988. The walkout lasted for five months.

Compiled by Andrew Prince and Trey Graham from reporting by Kim Masters.